1. Technical Field
The present disclosure relates to a method for forming an LED (light emitting diode), and more particularly, to a method for distributing phosphor particulates on an LED (light emitting diode) chip of the LED.
2. Description of Related Art
As new type light source, LEDs are widely used in various applications. A conventional LED includes a base, a pair of leads fixed in the base, a die mounted on the base and electrically connected to the leads and an encapsulant secured to the base and sealing the die. In order to produce white light, the die is made of a predetermined material to emit blue light, and large quantities of yellow phosphor particulates are doped in the encapsulant. The yellow phosphor particulates absorb the blue light from the die and are excited thereby to produce yellow light. The yellow light mixes with the blue light to generate white light.
There are two methods in the art to distribute the phosphor particulates on the die. One method is to dispose a shade around the die, and then spray the phosphor particulates on the die via a nozzle. However, the method leaves a large number of phosphor particulates on the shade, causing waste of the phosphor. The other method is to directly dispense the phosphor particulates on the die. This method is also unsatisfied since the phosphor particulates are not distributed uniformly.
What is needed, therefore, is a method for distributing phosphor particulates on an LED chip which can overcome the limitations described above.